/* =========================================================
   Design tokens
   ========================================================= */
:root {
  --font-serif: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Georgia, "Times New Roman", serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;

  --color-bg: #fbfaf8;
  --color-text: #1c1a17;
  --color-text-muted: #6b6459;
  --color-rule: #e2ddd4;
  --color-accent: #ea7e4a;

  --measure: 68ch;
  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 1.75rem;
  --space-4: 3rem;
  --space-5: 5rem;
  --space-6: 8rem;

  --tap-min: 44px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #161513;
    --color-text: #ece7de;
    --color-text-muted: #948c7e;
    --color-rule: #2c2a25;
    --color-accent: #eaa972;
  }
}

:root[data-theme="light"] {
  --color-bg: #fbfaf8;
  --color-text: #1c1a17;
  --color-text-muted: #6b6459;
  --color-rule: #e2ddd4;
  --color-accent: #ea7e4a;
}

:root[data-theme="dark"] {
  --color-bg: #161513;
  --color-text: #ece7de;
  --color-text-muted: #948c7e;
  --color-rule: #2c2a25;
  --color-accent: #eaa972;
}

/* =========================================================
   Reset
   ========================================================= */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-serif);
  font-size: 1.0625rem;
  line-height: 1.65;
  overflow-x: hidden;
}

h1, h2, h3, p, ul, li, form, fieldset {
  margin: 0;
  padding: 0;
}

ul {
  list-style: none;
}

a {
  color: inherit;
  transition: color 0.15s ease;
}

a:hover,
a:focus-visible {
  color: var(--color-accent);
}

img {
  max-width: 100%;
  display: block;
}

/* =========================================================
   Structural / UI type — lowercase, tracked, sans
   ========================================================= */
.structural,
.site-nav a,
.theme-toggle,
.section-label,
.profile-links a,
.entry-meta,
.entry-view,
.toggle-btn,
.contact-form label,
.submit-btn,
.site-footer {
  font-family: var(--font-sans);
  text-transform: lowercase;
  letter-spacing: 0.04em;
}

/* =========================================================
   Header / nav
   ========================================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-rule);
}

.site-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  max-width: 42rem;
  margin: 0 auto;
  padding: var(--space-2) var(--space-3);
}

.site-nav a {
  display: inline-flex;
  align-items: center;
  min-height: var(--tap-min);
  font-size: 0.875rem;
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color 0.15s ease;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--color-accent);
}

.theme-toggle,
.nav-toggle {
  align-items: center;
  min-height: var(--tap-min);
  font-size: 0.875rem;
  color: var(--color-accent);
  padding: 0;
  border: none;
  background: none;
  cursor: pointer;
}

.theme-toggle {
  display: inline-flex;
  transition: opacity 0.15s ease;
}

.theme-toggle:hover,
.theme-toggle:focus-visible {
  opacity: 0.7;
}

.site-nav ul li:last-child {
  margin-left: auto;
}

.nav-toggle {
  display: none;
}

/* =========================================================
   Layout
   ========================================================= */
main {
  max-width: 42rem;
  margin: 0 auto;
  padding: 0 var(--space-3);
}

.section {
  padding: var(--space-5) 0;
  border-bottom: 1px solid var(--color-rule);
  scroll-margin-top: 4.5rem;
}

.section:last-of-type {
  border-bottom: none;
}

.section-label {
  font-size: 0.875rem;
  color: var(--color-accent);
  margin-bottom: var(--space-4);
}

.updates .section-label {
  margin-bottom: var(--space-1);
}

.about .section-label {
  margin-bottom: var(--space-3);
}

.updates-note {
  margin-bottom: var(--space-4);
}

/* =========================================================
   Hero
   ========================================================= */
.hero {
  padding-top: var(--space-6);
}

.hero-name {
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: clamp(2rem, 6vw, 2.75rem);
  line-height: 1.15;
}

.hero-tagline {
  margin-top: var(--space-1);
}

/* =========================================================
   About
   ========================================================= */
.about-grid {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-areas:
    "intro-row intro-row"
    "teaching  teaching"
    "links     research"
    "degrees   degrees";
  column-gap: var(--space-4);
  row-gap: var(--space-3);
}

.about-grid p {
  max-width: var(--measure);
}

button.about-toggle {
  display: none;
}

.about-intro-row {
  grid-area: intro-row;
  display: flex;
  align-items: flex-end;
  gap: var(--space-4);
}

.about-intro {
  flex: 1;
}

.about-photo {
  flex-shrink: 0;
  height: 7rem;
  width: auto;
  border-radius: 10px;
}

.about-teaching {
  grid-area: teaching;
}

.about-research {
  grid-area: research;
}

.about-degrees {
  grid-area: degrees;
}

.profile-links-group {
  grid-area: links;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-top: 6px; /* optical alignment against the adjacent paragraph's cap-height, not a spacing-scale value */
}

.profile-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.profile-links a {
  display: inline-flex;
  align-items: center;
  min-height: var(--tap-min);
}

/* =========================================================
   Publications / citation list
   ========================================================= */
.citation-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  max-width: var(--measure);
}

.citation {
  font-size: 1rem;
}

.citation[hidden] {
  display: none;
}

/* =========================================================
   Recent work entries
   ========================================================= */
.entry-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.entry {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-1) var(--space-2);
}

.entry[hidden] {
  display: none;
}

.entry-title {
  font-family: var(--font-serif);
  font-size: 1.0625rem;
}

.entry-preview {
  flex-basis: 100%;
  max-width: var(--measure);
  font-size: 1rem;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 3;
  overflow: hidden;
}

.entry-preview[hidden] {
  display: none;
}

.entry-full {
  flex-basis: 100%;
  max-width: var(--measure);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  font-size: 1rem;
}

.entry-full[hidden] {
  display: none;
}

.entry > .toggle-btn {
  margin-top: 0;
}

.entry-meta {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

/* =========================================================
   Toggle button
   ========================================================= */
.toggle-btn {
  display: inline-flex;
  align-items: center;
  min-height: var(--tap-min);
  margin-top: var(--space-3);
  padding: 0;
  border: none;
  background: none;
  cursor: pointer;
}

.profile-links a,
.entry-view,
.toggle-btn {
  font-size: 0.8125rem;
  color: var(--color-accent);
  text-decoration: underline;
  text-decoration-color: transparent;
  text-underline-offset: 5px;
  transition: text-decoration-color 0.15s ease;
}

.profile-links a:hover,
.profile-links a:focus-visible,
.entry-view:hover,
.entry-view:focus-visible,
.toggle-btn:hover,
.toggle-btn:focus-visible {
  text-decoration-color: currentColor;
}

/* =========================================================
   Contact form
   ========================================================= */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  max-width: 32rem;
}

.contact-form label {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin-top: var(--space-2);
}

.contact-form input,
.contact-form textarea {
  font-family: var(--font-serif);
  font-size: 1rem;
  color: var(--color-text);
  background: transparent;
  border: 1px solid var(--color-rule);
  border-radius: 2px;
  padding: var(--space-1) var(--space-2);
  min-height: var(--tap-min);
}

.contact-form textarea {
  resize: vertical;
}

.contact-form input:focus-visible,
.contact-form textarea:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 1px;
}

.submit-btn {
  align-self: flex-start;
  min-height: var(--tap-min);
  min-width: var(--tap-min);
  margin-top: var(--space-3);
  padding: 0 var(--space-3);
  border: 1px solid var(--color-accent);
  border-radius: 2px;
  background: var(--color-accent);
  font-size: 0.875rem;
  color: var(--color-bg);
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease;
}

.submit-btn:hover,
.submit-btn:focus-visible {
  background: transparent;
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* =========================================================
   Footer
   ========================================================= */
.site-footer {
  max-width: 42rem;
  margin: 0 auto;
  padding: var(--space-4) var(--space-3) var(--space-5);
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

/* =========================================================
   Responsive
   ========================================================= */
@media (max-width: 40rem) {
  :root {
    --space-5: 3.5rem;
    --space-6: 4.5rem;
  }

  .site-nav {
    padding: var(--space-2) var(--space-3);
  }

  .nav-toggle {
    display: inline-flex;
  }

  .site-nav ul {
    display: none;
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-2);
    max-width: none;
    margin: 0;
    padding: var(--space-2) 0 0;
  }

  .site-nav ul.nav-open {
    display: flex;
  }

  .site-nav ul li:last-child {
    margin-left: 0;
    margin-top: var(--space-1);
    padding-top: var(--space-2);
    border-top: 1px solid var(--color-rule);
    width: 100%;
  }

  .about-grid {
    grid-template-columns: 1fr;
    grid-template-areas:
      "intro-row"
      "about-toggle";
  }

  .about-grid.about-expanded {
    grid-template-areas:
      "intro-row"
      "teaching"
      "research"
      "degrees"
      "links"
      "about-toggle";
  }

  button.about-toggle {
    display: inline-flex;
    grid-area: about-toggle;
    margin-top: 0;
  }

  .about-grid:not(.about-expanded) .about-collapsible {
    display: none;
  }

  .about-intro-row {
    flex-direction: column-reverse;
    align-items: flex-start;
  }

  .entry {
    flex-direction: column;
    gap: 0.25rem;
  }
}